The present invention is related to battery monitoring, and more particularly to systems and methods for detecting internal battery degradation.
A number of electronic devices utilize rechargeable batteries and associated charging systems. A rechargeable battery may be repeatedly charged and discharged over the course of its useful life. The process of charging and discharging is generally performed without incident other than the typical operational degradation of the battery over the course of operation. Indeed, most battery failure mechanisms operate to gradually decrease useful battery life and do not cause a safety hazard.
At times one or more mechanisms may come into play that result in the catastrophic battery failure. For example, during operation manufacturing defects or gradual structural or chemical degradation may result in the separation of small metallic particles or other conductive particles inside of a battery. These particles can cause internal short circuits that in some cases may result possible fire or explosion of the battery. Such a catastrophic battery failure may thus result not only in loss of the battery itself, but may result in considerable property damage and personal injury.
Some electronic devices employ an external protection circuit to detect increasing battery temperature or overheating. When an overheating event is detected, the battery may be disconnected from a circuit to which it is connected. This approach offers some ability to limit damage to an external circuit due to undesirable battery behavior, however, at times the overheating is a sign of an irreversible process that ultimately results in a fire or explosion regardless of any process disconnecting the battery from surrounding circuitry. Thus, while the aforementioned external circuits offer some level of protection, the possibility of fire or explosion still remains.
Thus, for at least the aforementioned reasons, there exists a need in the art for advanced systems, circuits and methods for determining potential battery failure.